Conversion of Overhead Contact Systems Poles to Pantographs

Luigi Di Michele, C.E.T. Peter Hrovat, P. Eng. Transit Commission Toronto Transit Commission Toronto, Ontario, Canada Toronto, Ontario, Canada

Richard J. Vella, Bsc. EE. Paul F. White Toronto Transit Commission HNTB Corporation Toronto, Ontario, Canada Chelmsford, MA USA

INTRODUCTION design a new streetcar in 1972. In August of 1973, TTC placed an initial order for 200 new vehicles from OTDC, The Toronto Transit commission (TTC) has a total ten prototypes of which would be designed and built by a streetcar track mileage of 81 km [51 miles], over 100 manufacturer in Switzerland called Schweizerische complex intersections and has operated streetcars with Industrie Gesellschaftbefore (SIG).The order for 10 Swiss trolley pole current collectors since it began operating in CLRV models was cut back to six in the late 1970’s to 1921. Prior Companies had used pole operation since the provide parts needed to build an experimental articulated inception of electric streetcar in August of 1892. The version of the design but only one articulated prototype more recent PCC cars used trolley poles and the overhead was built. In the meantime, the new SIG cars started to remained compatible for trolley poles. The replacement arrive in 1977 and 1978 with the UTDC cars starting in vehicles to the PCC car, known as the Canadian Light 1979. Revenue service started in September of that year. Rail Vehicle (CLRV) manufactured by Hawker-Siddeley In 1988 the first of 52 ALRV’s was entered into revenue at Thunder Bay Ontario, were equipped with trolley pole service. By 2009 they began reaching the end of their current collectors of the same type and style as the PCC useful life and the City of Toronto and the Toronto cars, being a 14 foot trolley pole with a one and one-half Transit Commission began the process of replacement. inch diameter pole butt at the end, an Ohio Brass Form-11 Light Weight two spring trolley base and Type-J Trolley The power draw requirements for both types of Harp with carbon shoe. vehicles were nearly the same being 272 kw (453 amperes) and 260 kw (433 amperes) for the CLRV and Two types of cars were purchased, double truck ARLV respectively. The collector shoes could handle this single cars CLRV (Fig. 1) and three truck, two section current value adequately without overheating or undue articulated cars ALRV (Fig. 2). The articulated version carbon wear and the trolley poles were able to negotiate was 23.164m [76.0 ft] ft long while the non-articulated the existing overhead contact system (OCS) without issue. version was 15,226m [49.95 ft] long with truck centers at 25 ft. The cars are single end and turn direction by EXISTING OVERHEAD SYSTEM accessing loops at terminal points. Overhead System Type TTC placed an initial order for 200 new vehicles from the Ontario Transit Development Corporation later The existing OCS that was in place worked named Urban Transit Development Corporation (UTDC) extremely well and the Commission wanted to retain it and with Hawker-Siddeley, embarked on a project to but determined it was not adaptable for

Page 1 of 14 operation. The system was a traditional direct suspension Fiberglass rod insulators were attached to each side of the double insulated system using 1/4” and 5/16” span wire suspension piece to add insulation as span wire was steel. made up with preformed end fittings, fiberglass rod insulators used for span wire insulation at poles, with The pullover accommodated large angles for AGC span wire hanger or cap and cone hangers with 12 enhanced pullover spacing and the curve rail smoothed inch HS clamp ears to hold the trolley wire, No-Bo out the abrupt angle so the shoe could pass through it. section insulators, Type SH trolley frogs and crossover Multiple pulloffs were eliminated by this method and the pans and a 2/0 grooved alloy 80 bronze trolley wire. It curves of grand unions and wyes became more was a classic overhead contact system that functioned aesthetically pleasing as a result. very well with trolley pole current collectors, and was very easy to maintain. The Spadina line also used OCS support poles that used ornamentation, architectural enhancements and were joint use with city streetlights. Section Insulators

One OCS feature unique to Toronto was the use of No-Bo section insulators with a large diode feeding the neutral section (Fig. 11). TTC standards dictate that section insulators are to be non-bridging for safety and the older No-Bo style section insulator provided this feature. Operational rules required the streetcar operators to coast through the section insulators so arcing would not occur and minimize insulator burning. The spacing of section insulators at 20 feet apart prevented regenerative section Fig. 1 bridging across a single section insulator and this arrangement was introduced with the operation of the CLRV’s due to their regeneration capability.

Under normal operation, the streetcar passes through the first section insulator onto the neutral zone but receives power from the next power section through a large capacity diode. The streetcar then passes through the second section insulator into the next power section. In the event the power section in the adjacent section was dead, the car would pass through the first section insulator and as it regenerated from braking, the diode blocked the current from passing into the dead section and prevented it from becoming alive.

Fig. 2 OCS Support Poles and Bracket Arms

The Commission used tubular three section steel The Spadina line, which was completely rebuilt by poles of varying sizes and heights which were directly 1997, used different OCS hardware and design criteria embedded into the earth with a concrete foundation than the core system. Suspension of contact wire was with around the embedded section. As these corroded over stitch or delta configuration using a line insulator with a time, replacement was necessary and a decision was made pulley, synthetic rope and two contact wire clamps for to standardize on one type of pole, which was an extra tangent construction. heavy steel pipe of constant diameter. Three sizes were used, an 8 inch, a 10 inch and 12 inch pipe with lengths Curves used pullovers with a long clamp ear referred varying to that needed for each particular installation. The to as a curve rail having a clamp that bolted to the rail in standard poles are direct embedded in a concrete two places with greater spacing. Attached in the center of foundation. Anchor base poles are utilized in certain this was a boss for screwing a suspension piece on. This locations. was bolted onto the clamp for pulling it into alignment.

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The Commission has many locations where bracket arms are used to support the trolley wire. They are typically 2 inch standard weight pipe, galvanized and attached to the pole with a pipe insulator and pole clamp. The arm uses a guy wire to support it. Some areas of the system required non-standard bracket arms for streetscape enhancement and interesting styles were used on St. Clair and Spadina Avenues.

Feeder Cables

Feeder cables are typically 1000 kcmil copper Fig. 3 insulated cable strung aerially on poles or in underground conduits. Feeder taps connected to the aerial cables are run to the trolley wire and connected to it with a bronze feeder ear. Underground taps rise in conduit, outside the OCS pole and run to the trolley in the same manner as the aerial taps. Cables are attached to poles with fiberglass standoff insulators attached to the pole with galvanized steel pole bands.

Span Wires

Span wires consist of 5/16” seven strand galvanized steel guy wire for suspensions and pulloffs, 3/8” seven strand galvanized steel guy wire for back guys and heavy Fig. 4 loads and 1/4” seven strand galvanized steel guy wire for steadying bracket arms. Typically at poles, a 5 ft. fiberglass rod strain insulator attached to the span wire to provide secondary insulation as the trolley wire is PRELIMINARY ENGINEERING attached to a line insulator which attaches to the span wire. At the bracket arms, insulators were placed in the Current Collectors span wire steady spans at the pipe. The Commission maintains double insulation at a minimum. One of the primary concerns of the Overhead Section was the compatability of the existing overhead contact Originally, span wires were terminated by serving the system with the new vehicle’s pantograph current strands around itself but this method has been replaced collector. As TTC had no experience with pantograph with Preformed End Fittings. operation, they contacted several transit agencies and conducted meetings to find out their experiences with NEW STREETCARS pantograph operations and pole to pantograph conversions. Commission line supervisors traveled to When it was decided by the Commission that new Philadelphia to meet with their counterparts and were able streetcars were needed due to the CLRV and ALRV to receive valuable information on pantograph operation streetcars would be nearing the end of their useful life, or trolley pole to pantograph conversion. Commission the Commission began searching for a manufacturer to engineers also contacted and met with consultants who build the streetcars. In 2009, it was announced that the had pole/pantograph conversion experience. Bombardier Flexity Outlook would be the replacement vehicle. Testing began in 2013 and revenue service Interestingly, the department did not want to run with started on August 31, 2014 on the route. pantographs as the entire overhead network would have to be rebuilt but the new streetcars had significant current These cars are five section articulated vehicles 100 ft draw of 100% more current, well above that of the long with low floor easy access. They are single ended existing streetcars. The department engineers explored and use track intersections and loops to turn around. various options for current collectors including articulated Figures 3 and 4 show the operation of the new car with a trolley pole and a pantograph.

Page 3 of 14 trolley shoes and a longer carbon shoe and holder (Fig. 5 Preliminary Engineering and 6) The new streetcars were to be phased in and delivered over a period of time as the entire order could not be delivered at once. Therefore, the overhead system would have to be able to allow operation of poles and pantographs for an extended period of time.

Commission engineers reviewed the information provided to them from the other agencies and decided to have consultant assistance with the process of overhead conversion due to the design effort required. They interviewed various firms and manufacturers and formed Fig. 5 an approach to see which consultants could assist them. They also wanted to ascertain the compatibility of different OCS manufacturer’s components for use on the system and contacted several companies.

The Commission placed a tender for overhead design services and chose three firms that would be assigned tasks, SDJ Electra, Gannett Fleming, and HNTB Corporation. The Commission also approached three OCS suppliers for design assistance and material components to be used in the consultants designs. Kummler + Matter and Impulse NC were chosen as the third manufacturer did not want to assist with the design effort.

As part of the initial design effort, HNTB was asked to prepare a report for pantograph operation in the Eglinton Tunnel, part of the Metrolinx new streetcar Fig. 6 project. There were extremely tight clearances and low trolley wire heights and the Commission engineers Extensive testing was undertaken with an ALRV that needed information on the various type of OCS that could was altered to draw the same current through the trolley be used in such a situation. In HNTB’s report, optional pole as the Flexity streetcar would draw using the longer overhead systems were presented and the advantages and TTC shoe as the shown in Fig. 5. It was disadvantages highlighted. The optimal system was rigid surmised that the longer carbon would be able to handle conductor rail as current collection for the Metrolinx the added current draw of the new streetcars. To negotiate system was all pantograph and separate from the core trolley frogs, the side walls of the shoe were kept the TTC system. same length as the standard shoe but the shoe body and carbon were lengthened. The long shoe worked extremely A fundamental difference with the Metrolinx system well tracking through trolley frogs, crossover pans and was that it had standard gage track of 4.71 feet rather that curve pullover ears but with sustained currents of over the TTC standard of 1.4953 m [4.906 feet]. This track 1,000 amperes flowing, it could not resist the heating gage difference unfortunately made assurance that the two affects and at one point during the testing, the shoe systems could never be easily linked. became so hot that it glowed red. Engineering Assignments It was evident from this testing that trolley poles with a modified carbon shoe for additional current draw were The Commission engineers have historically insufficient and pantograph current collectors had to be designed their overhead system and any changes, adopted. From this determination, preparations were made additions or new construction have been and still are to convert the overhead system. undertaken by the Commission’s Overhead Section. The Commission also does their own overhead construction NEW OVERHEAD SYSTEM and maintenance as their crews are highly skilled and trained for trolley line work. One of the highlights of their

Page 4 of 14 abilities is to work the lines alive and do work with streetcar systems, a review of design and construction service running. Their mantra is to keep the service methods was undertaken. running under any and all situations only if it can be done The Commission had developed ways to measure and safely. layout the overhead on curves for trolley pole operation The engineering staff and the line maintenance and and discussions with HNTB about this evolved into an construction crews work closely together and alternative approach than was currently being used which commiserate on designs, hardware, service situations to provided an easier pulloff offset location with pantograph ensure that what is specified in the designs is what will be operation. able to be constructed easily, efficiently and In laying out curves, crews located the trolley frog, economically. In short, the engineering and construction pullovers and offsets according to the design drawings forces are partnered for the best OCS possible. prepared by the engineering staff. The frogs are located first and then all pullovers determined from the frog as Engineering the OCS this is the reference point. Trolley frogs are located from a measurement at the end of the track casting of point mate The first two designs undertaken and constructed street switches to the back of the frog hanger and this has were the Fleet loop and the Earlscourt Loop with HNTB not changed. Corporation doing the former and SDJ/ELCON Associates doing the latter. Earlscourt Loop was designed When Commission engineers prepare an OCS design and built with ImpulseNC hardware and Fleet Loop with drawing, they include the track rails and have a detailed Kummler + Matter (K+M) hardware. During the track switch casting in the track to exact scale. For construction, the line crews evaluated the different types intersection drawings, a table is made and placed in the of overhead hardware from the two manufacturers drawing that provides the frog location measurement, i.e. supplying the equipment and made decisions on what end of casting (E.O.C.) to back of frog hanger. Each track material worked the best for them. They considered ease switch is provided a number in the drawing so it can be of construction, ability to make adjustments, weight of the referenced in the table. Frogs are typically located directly components, appearance of the OCS and operation over the center of the track but if a switch is in a curve, through the completed overhead by streetcars. Various the frog may have to be offset from the track centerline to components from K+M and ImpulseNC were chosen accommodate proper pole tracking and each location is including some standard TTC designed hardware and a determined on a case by case basis. master material list (MML) was established with many of the specialty hardware from K+M. Frogs are not cut into the trolley wire but the wires run through the frogs and approach tips are used. Prior to The MML had each component listed by description, the start of new construction, the existing turnout 2/0 vendor part number, and TTC listing number. A part trolley wire was terminated at the frog hanger and either a number 88 was for Phillystran 11 mm Diameter Span frog guy was used or the suspension spans attached to the Rope, part number 1 was for 4/0 alloy 80 grooved bronze frog to hold it in place. It was recommended by HNTB trolley wire, part number 73 was for a turnbuckle eye & that any new construction at trolley frogs have the turnout eye, and so forth. This allowed a consistency between wire run completely through the frog to a point beyond various loop, yard and intersection designs, ensured that the track rail of 0.46 m [1.50 ft] where the deadend would the different designers would call out a particular item be attached to the span rope. with the same part number, and identify it in their material list in the same manner as the Commission The reasoning for this is that when total pantograph engineering staff was listing it. HNTB presented this operation is in place, the trolley frogs can be removed method to the Commission engineers during the first Fleet from the trolley wire and replaced with a cross contact Loop design and it became the standard for all designs wire clamp and jumper cable without having to splice from thereon. trolley wires or adding additional deadends as they will already be in place. HNTB also assisted the Commission engineers with establishing new standards of design criteria and Offsets for trolley wire on curves for all pole construction for joint operation of poles and pantographs. operation were previously measured from the inside curve The Commission had in place established standards and rail towards the center of track during this period of methods for design but they were based on exclusive operation. This was changed for joint operation to having trolley pole operation and as HNTB had significant all offset measurements taken from the center of track experience with conversion, operation and engineering towards the inside of the curve. Staggers on tangent track

Page 5 of 14 were measured from the center of track towards the rail The New OCS System and continue to be done in this manner. Since the pantograph is directly over the center of a truck, and its A standard overhead system was established and used centerline coincides with the track centerline, it was for the design and construction of the new OCS. The logical to measure offsets and staggers from the former direct suspension system was replaced with an centerline. Spacing of the pullovers around a curve starts elastic suspension system consisting of an inclined stitch at the back of the frog hanger and goes in the direction of (delta) supporting the contact wire at spans and bracket traffic to the end of the curve. arms on tangent, and flying pullovers on curves where they would float creating a soft suspension. Under With all pole operation, trolley wire offsets from the bridges, a rolling suspension was used and in the Queen’s center of the track were dictated by the radius of the track Quay to Union Station tunnel, elastic arm suspension was curve so the trolley pole would have its shoe tangential to employed. Contact wire size was increased for electrical the pullover. Commission engineers determined the capacity and wear characteristics. Since the system was to correct offset with formulas and graphics used in the be dual operation for an extended period of time, trolley design. The offset for a 15.2 m [50 feet] with the CLRV’s frogs and crossing pans continued to be used. is 610 mm [24 inches] and provides proper pole tracking through a curve. The dimensions of the pantograph on the Span Wire new Flexity streetcars are such that the wire on a 15 m curve would place it at the edge of the horn at the pullover The Commission standard span wire was changed and on the horn between pullovers. This was an unsafe from 5/16” 7 strand galvanized steel guy strand to non- condition and the Commission engineers designed a conducting span rope from Phillystran®. The size and compromising offset that would work for both types of type chosen was HTPG 11200 with a breaking strength of current collectors. They developed a range of travel from 50 kN [11,200 ponds] and a diameter of 11 mm [0.42 the center of the track that varied from 229 mm to 300 inches]. This material has an Aramid fiber core with an mm. As long as the trolley wire was in this location on the extruded polyethylene jacket and is completely non- curve, poles could track without dewirement and the conducting and of high dielectric strength. It is secured at pantograph could traverse the curve without fear of the terminations with either preformed end fittings or trolley wire leaving the horn. On tangent track, the wire NicoPress sleeves. In both cases a thimble is used to form was staggered by 80 mm [3.14 inches]. the loop and prevent abrasion. The preform has a made up length of 1294.4 mm [51 inches] so in tight clearance Each drawing has pulloff spacing indicated so the locations the use of four NicoPress sleeves is 254 mm [10 line crews can layout the curve on the track itself and inches] in length. In the event the sleeves are close to a locate the overhead wire pulloffs directly over the mark grounded structure, they are taped for additional on the street. If there is a bust in the measurements for insulation. some reason, the crews can alter the pulloff spacing in their marks on the street to ensure proper location of This material has been a complete replacement for all pulloffs before they start constructing. This rarely occurs span wire used in the OCS with the exception of back as the drawings are to scale. guys which are still 3/8” steel guy wire. An interesting feature of span rope is its very light weight and ability to All overhead designs are superimposed on the official shed ice easily as it does not adhere to the rope jacket. track geometry design drawings which are to scale and exactly what is laid out and constructed in the street so the The line crews found favor with it as it is non- only way to misalign the OCS would be through a conducting and can be run over energized trolley wires typographical error in the OCS drawings. As all without fear of short circuits, electric shocks or burn Commission designs are double checked for accuracy, downs. Its light weight made it easier to handle and it typos are rare. didn’t have “coil memory” that would cause it to spring off the wire reel as steel span wire did. The OCS layout drawings included the height of the span wire on the pole, the tension in the span wire at the Contact Wire worst loading conditions, the resultant rake direction and the bending moment. All of this information became The contact wire was changed from 2/0 alloy 80 somewhat confusing for the construction crews so on later trolley wire to 4/0 alloy 80 trolley wire, all grooved. design drawings, only the span wire heights and the Cadmium bronze was initially used but this was changed resultant rake direction arrow was shown on the drawing. to magnesium copper with 85% conductivity due to concerns of Cadmium being carcinogenic. The

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Commission determined decades ago that bronze trolley held. There is no flexibility in the suspension and the wire was less susceptible to accelerated wear and fatigue contact wire can be worn at this point as a hard spot cracking than hard drawn copper trolley wire and has develops. continued its use. It can be pre-stressed to limit creep and in an environment where temperatures can range well Curve Suspension below zero from -40°C to 49°C [-40°F to 104°F], this wire works very well and is superior to copper. Curve suspension uses flying pullovers that have a curve line insulator with a suspension eye to which is Contact wire on straight runs is tensioned to full attached a 4 mm diameter steel hanger wire with two value and when on tight curves such as intersections and loops. These have a non-conducting J thimble inserted in loops, it is half tensioned. With the temperature ranging the loop to prevent abrasion and add a measure of from -40° C to +40° C, the mean temperature chosen was insulation. A curved pullover rod is placed in the free end 16° C [60° F] and the full tension was 890.8 DaN [2,002 of the hanger wire and has a clamp ear attached to its lbs] and at half tension 485.0 DaN [1,090 lbs]. The curved threaded end (Figure 7). Commission refers to the reduced tension as half tension but in reality, it is a reduction of full tension and is shown The advantage of these over the old cap and cone on Table 1. hangers is that the curve pullover assembly is clamped to the span wire without cutting into the wire. This allows

Contact Wire Tension Chart greater flexibility in adjustment and faster construction time. The pullovers are either single rod or double rod Half Tension Full Tension Temp °C (daN) (daN) where angles between 2-8 degrees use one rod. For angles -40 1502.7 4557 over 8 degrees, two rods are used, spaced 710 mm [27.95 inches] apart at the contact wire. The rod is curved and -18 1050.2 1562.8 16 485.0 1090.0 when suspended in the curve, it affords good clearance to 29 352.4 644.8 the pantograph when lifted up from the pressure of the 40 287.0 498.0 pantograph even during elevated temperatures when the Table 1 contact wire has low tension.

A long clamp ear referred to as a curve rail is Suspension Assemblies screwed onto the end of the pullover rod for securing the contact wire. The rail is 600 mm [23.6 inches] long and Tangent Suspension bends to a smooth curve allowing trolley poles to traverse them without banging. The contact wire is suspended from the span rope or bracket arm with different suspension hardware. On tangents, a stitch assembly is used consisting of a line insulator, a pulley through which a 3 meter [9.84 feet] long Aramid stitch rope with terminations passes. It is attached to trolley wire clamps that have a bracket which is adjustable 180 degrees to the horizontal of the contact wire. This allows the stitch to be offset for stagger creating an inclination where the bracket can be adjusted so that the trolley wire clamp sits vertically on the wire. This is important as it prevents the trolley pole collector shoe from scrubbing against the side of the clamp.

Inclined pendulum hangers are also used but to a limited degree. These can be short or long but also Fig. 7 provide an elastic suspension as the contact wire is free to lift up unencumbered as pantographs or trolley poles pass Trolley Frogs and Crossover Pans by preventing accelerated wear of the contact wire. Trolley frogs will be used during the transition period Rigid direct suspension is also used but to a limited of pole/pantograph operation. Frogs are standard SR type degree. This is where the line insulator is clamped to the with renewable tips and are 10 degrees. They are placed span rope with a clamp ear to which the contact wire is in the wire directly over the track centerline at a particular

Page 7 of 14 location from the end of the point mate casting where the gliders but was sloped so that pantographs could pass trolley pole shoe becomes 10 degrees to the tangent wire through. as the streetcar takes the curve. This is done for both taking and trailing operations.

The main line contact wire runs straight through and the frog is clamped to it. The turnout wire runs through the frog beyond the frog where a deadend clamp is attached outside of the tracks by 0.46 m [1.50 feet] outside of the running rail. With the old system, the turnout contact wire was deadended at the frog. Running the turnout wire beyond the frog is for future all pantograph operation when the frogs will be dropped out and the deadend wire will become a turnout crossing wire (Figure 8). A cross contact clamp will be installed along with an equalizing jumper.

Operation through the frogs with pantographs requires gliders to prevent the pantograph carbons from Fig. 9 striking the frog hanger. Gliders are attached to the frog after it is installed. The glider allows poles to pass through with clearance. The entering end of the gliders have a bar (anti-trapping guard) closing them to prevent a dewired trolley pole from becoming tangled into the gap between the glider and the frog body (Figure 9).

Fig. 10

Section Insulators

The Commission used the standard No-Bo section insulator for PCC and CLRV operation in a special Fig. 8 arrangement. With the advent of CLRV operation, there was concern about accidently energizing a dead power section if a CLRV regenerated into the dead section with Crossover pans accommodate poles and line crews working on the line. To prevent this type of pantographs and the original design called for utilizing the accident, Commission electrical engineers devised a existing SR crossovers with a glider made of 4/0 bronze unique method of sectionalizing the line at power section trolley wire. It was configured in such a way that when boundaries. installed on an adjustable crossover, the glider could rotate to the final angle. An adaptation to this was made This method used two section insulators spaced 6.09 by K+M and is shown in (Figure 10). Ninety degree meters [20 feet] apart. As the piece of contact wire crossings used a completely new pan that did not have between the two section insulators was normally dead with no feed, the engineers devised a method of feeding

Page 8 of 14 this “dead zone” with a diode. A 2,500 volt, 1,400 amp diodes. This arrangement was the same as the original disk diode was placed in an assembly with a heat sync on section insulator arrangement except that the runners the second section insulator and the feed coming from the allowed the streetcars with pantographs or trolley poles to power section the vehicle would be travelling into. The pass through with no interruption of current collection yet dead trolley wire was normally energized through the preventing bridging of the runners (Figure 12). diode until the power section feeding it went dead. When this occurred, the middle piece of trolley wire also went Figure 13 shows a schematic of the diode dead. arrangement and power section separation. An interesting adaptation of this was used to provide automatic power The diode prevented current from passing from the section jumping during outages at the intersection of middle wire during regeneration into the dead power Broadview Avenue and Gerrard Street East where the section by the inherent nature of the diode. The 6.09 m four legs of the intersection are insulated diode section length of the middle contact wire was of sufficient length insulators and there is no feed at the intersection. Each to have the regeneration turnoff as there was no load to street is fed by different feeder cables and the diodes at keep it on so when the car passed onto the dead power each insulator allow current to flow into the intersection section wire, regeneration was turned off preventing but not out of it. This arrangement allows the intersection accidental energizing of the dead power section (similar to have power in the event one of the power sections to Figure 11). feeding the intersection goes dead (Figure 14).

Fig. 12

Fig. 11 In preparation for pantograph operation, it was determined that the existing No-Bo section insulators that had a 355.6 mm [14 inch] underrun would cause bridging when the pantograph passed through it. The arcing from trolley poles and the subsequent damage to the arcing clip, tip and insulated underrun could cause carbon chipping of the pantographs so engineers looked into a different type of section insulator. It was decided that a combination insulator Fig. 13 specifically designed for trolley pole and pantograph Bridge Suspension and Protection operation was necessary and one that allowed power to not be interrupted during passage of the current collector. Standard suspension under low bridges has been with K+M designed a special diode section insulator for this insulated wood trough to provide insulation between the type of operation consistent with the 6.09 m middle wire trolley wire and a dewired trolley poles to the grounded operation. Two insulators were used, one with the main bridge structure. The wire was directly attached to the diode and smaller diodes feeding the insulated conducting trough with barn hangers and clamp ears. A new style runners and the other section insulators with only small

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wood trough/spacer bar system would be in service along with the new conductor rail system. This would be a completely new type of conductor and operating system for the Commission and they asked HNTB to do this design.

HNTB accepted the task to design the new OCS for the station area and HNTB and Commission engineers worked closely together. A major obstacle was the tight radius track turnouts and curves which were in place, some as low as 13.5 meters [44.29 feet]. Conductor rail must be pre-curved for tight radii and the minimum radius for Furrer + Frey rail was stated to be 40 m [131.2 ft]. It Fig. 14 could be bent to 18 meters but running the trolley wire through it would be difficult. HNTB designed the bar as trough with barn hangers and clamp ears has been used pre-curved segments in a chord fashion with the contact which is a U shaped fiberglass structural member wire continuous through the bar. As the bars were not connected to the bridge steel. An insulated rolling contact connected and jointed, jumper cables were used to wire support is bolted to the trough and this provides an provide electrical continuity. The bars had to be on either added measure of electrical protection and soft side of the wood trough and would alternate according to suspension. At the ends of the trough where the contact obstructions and locations at track switches. wire rises up to the next supporting span wire, the rolling support has a vertically curved curve rail to smooth out Where the conductor rail ended and pantographs had the vertical angle between the trough and the adjoining no running surface, transition copper tubes were used and span. The trough and rolling suspenders are so arranged connected directly to the side of the wood trough. These that both poles and pantographs can safely and easily were adjustable vertically to match the bottom elevation negotiate the bridge and Figure 15 illustrates this. of the conductor rail. This allowed a smooth transition for the pantographs throughout the overhead in the station area.

Another design challenge was the fact that a large fire door was in place that had at one time operated. It had been taken out of service and kept in the up position and the wood trough and conductor bar run directly under and through the door area. Operations now requires that the doors be made operable again and provision has been made to install a door bridge that will break the overhead when the door is closed and allow pantographs and trolley poles to operate through the OCS when the door is up. There was some difficulty in having a conductor rail door bridge design as the original supplier insisted on designing the arrangement as well as supplying the Fig. 15 material. Commission engineers searched for an alternative supplier and found one in KLK Rail Tech. Conductor Rail Installation The conductor rail supplied by this company could be St. Clair Station West, which is an underground loop pre-curved to 14 m [45.9 ft] and they were willing to station with two inclines leading from the street has an supply a door bridge and assist in any design effort by the overhead system consisting of wood trough and Universal Commission and their consultant. As it turned out, the Spacer Bar. At certain locations, the height of the station door bridge arrangement as finally designed was a ceiling is very low and other locations very high and the standard Impulse door bridge that was modified to have trough is either bolted directly to the ceiling or suspended approach runners and an insulated bridge for both from it. Engineers looked at various options and decided pantograph and trolley pole running. to use aluminum conductor rail as the contact system for pantographs. There was to be a period of time that the

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The plan of the design is to have the existing trough move with expansion/contraction of the contact wire and and bar system in place and the bar system installed next is constructed as a simple overlap (Fig. 19). They allow a to it. There will be phasing steps where the conductor rail trolley pole and a pantograph to pass through and have will be changed and the trough removed in stages until been used on trolley lines in Europe for many years. only conductor rail remains. Figure 16 shows the existing Trial runs with pantographs and poles reveal a very station area and Figure 17 shows design details of the smooth operation through the rails and the spring is conductor rail and wood trough. keeping the contact wire in a constant tension of 890 daN [2,000 lbs]. This method will be used on other lines as well after the trial period is over.

Fig. 16 Fig. 18

Fig. 17 Fig. 19 Constant Tension

Commission engineers were aware of the need for The spring device is composed of two basic constant tensioned overhead because of the extreme components, a take up spool and a spiral spring. The temperature range encountered in Toronto and explored take up spool is a composite of a circular spool and a options early in the design effort. A constant tensioned spiral cam which both rotate around a common shaft. spring device from K+M/Pfisterer that applies a constant The spiral spring is connected to the cam and the tension on the contact wire while the spring tension varies contact wire is anchored to a partially wrapped cable was chosen for trials (Figure 18). These springs have around the circular spool. As the contact wire expands been in extensive use in Europe as a replacement to and contracts, the cam and spool rotate compressing or balance weights and have proven safer in areas of expanding the spring. The changing force in the spring pedestrian traffic as there are no weights to fall down. is compensated by the changing moment arm provided The system has been installed on the new Cherry by the cam with a resultant torque system with a Street extension of the 514 line and uses expansion rails constant output force in the contact wire. from K+M that allow the contact wire to run through and

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Constructing the OCS The Commission also does conversion work on lines that have been temporarily taken out of service for track The Commission maintains a large work force of renewal and the overhead can be killed in these areas electrical workers who build and maintain the existing without affecting other parts of that particular power power system. All work is undertaken by section. With no streetcar operation and the overhead Commission employees who are trained, skilled killed, it can be removed and the line crews can rebuild journeymen linemen intimately knowledgeable with the OCS to the new standards very quickly. TTC’s overhead system. All of the new construction for the conversion of pole to pantograph was undertaken by A distinct advantage of the new standard OCS is the Commission forces and most of the work was done during use of high strength, non-conducting Kevlar rope. In the day with power on and streetcars operating. Night intersections or other parts of the line where the contact work was undertaken in locations where day time traffic wire is alive, these span ropes can be run over the existing made it impossible to maneuver the trucks without wires without fear of short circuits or arc flashes as the creating traffic jams or where long wire runs required the wire is non-conducting. It can lie on top of the energized power to be killed. contact wire and the ground or be handled by personnel on the ground without fear of electric shock. The crews are governed by strict safety rules and wear personnel protective equipment including fall OCS Operational Issues protection harnesses. Although chances of a linemen falling out of the tower are low, it is possible and the During the conversion process, several issues arose harness keeps the individual from doing so. Other with the operation of pantographs. The pantographs have protection includes hardhats, safety glasses, gloves, and an automatic drop down feature that if damaged in any arc resistant coveralls (Figure 20). way, it drops down. The feature was set so that the pantograph would drop down but so quickly that it would slam into lock down and break the frame insulators. This feature has been modified to lessen the impact of drop down so that insulators are not damaged.

The new streetcars have a feature similar to the old PCC cars where the motorman could back the car using a controller at the rear of the car. Operators sometimes failed to secure the trolley pole rope and the pole would snag into a frog, bend the pole and damage the frog gliders. A pantograph would then run through the damaged gliders and get snagged. New rules were put in place that during the transition period, only poles could be operated in the yards. Frog runners have also tipped and Fig. 20 caught pantographs but this is very infrequent and has been solved by more frequent monitoring of the areas of most concern and span wire adjustment. Crews are made up of a foreman, two lineman and a driver groundman and work from a platform line truck as The runners on the diode section insulators are this equipment provides sufficient working space for two positioned below the tension beams for the pantograph to linemen, OCS equipment and tools. run on without running on the bottom of the beams. Some installers have not completely adjusted the runner and One of the biggest advantages of the methods of they were too high causing the pantograph to run on the construction and maintenance which are practiced by tension beams. Once the runner was properly positioned, Commission line personnel is working the OCS while the pantographs ran through properly and smoothly. energized. In areas that can’t be accessed during daytime hours requiring night work where the contact wire must A buildup of carbon deposits from the carbon shoes remain energized, the crews can accomplish conversion and pantographs caused minor electrical tracking. When work without affecting service in that particular power power sections were killed, indication to power control section. In carhouses and yards, this is essential as was that the section was still alive. Wiping down the streetcars require power for auxiliaries such as air runners stopped the problem but carbon would continue to compressors. build up. The runner insulating material was changed

Page 12 of 14 from fiberglass to ceramic but uneven wear problems The Commission’s existing OCS was a traditional occurred where the metallic portion of the runner would system adopted for only trolley pole operation. The wear faster than the ceramic portion. An air gap insulator system is being converted to allow both trolley poles and at the runner connection is being looked into and appears pantographs to run on it and when all pantograph it will solve the problem. streetcars are running, further changes will be made for only pantograph operation of the OCS. Some arcing has occurred at the mid-portion of the insulator at runners where the two sections are fed from Initially, trial installations were undertaken using different power sections. This occurs when there is a large different manufacturer’s hardware with different difference of potential between power sections and the consultants designing the installations. Line crews streetcar is running through the insulator at full power. evaluated the hardware and ease of construction from the Magnetic blowout coils have been installed and this has designs presented and recommended what hardware solved the problem of arcing but does not allow a should be used. The steel span wire system was changed pantograph to pass safely through as the device hangs to Aramid span rope for ease of installation and safety. down. A different blowout with spread wing magnets has Engineers working with line crews developed a standard been tried but the magnets were not powerful enough and overhead system for TTC that the line crews would build the engineers are looking at different types of magnets. In to and that the consultants would design to. one instance, the arcing damaged the large heat sync diode so a decision was made to take it off of the insulator Overhead fittings were designed for joint operation and hang it on the section insulator suspension spans. This and new fittings and suspensions were created where also made the insulator lighter by reducing the weight. appropriate fittings were not available. Lines are being converted by TTC line personnel changing out the old The tension in the contact wire is full tension for overhead hardware and installing the new material both tangents and long radius curves and is half tension on during outages and with the contact wire energized and tight radius curves. Where the contact wires of the two service running. different tensions merge at trolley frogs, the half tension wire can become slack in hot weather and a pantograph The use of diode section insulators was retained with has pushed it up high enough that the horns snagged onto the arrangement of spacing for preventing accidental the full tension wire. This was rectified by putting spacers regeneration energizing of dead power sections. The between the two wires beyond the trolley frog similar to a section insulators were equipped with conducting runners knuckle to keep the wires moving up together. The first fed by diodes for all streetcars to pass through with power knuckles were two adjustable steady arms u-bolted but without section bridging. They are designed for together and then a special spacer was created with an accommodating poles and pantographs. insulating oval rod and two clamps for contact wire attachment. A special arrangement for feeding the intersection of Broadview and Gerrard was implemented with diode In general, problems have been more of an section insulators to allow the intersection to have power annoyance than systematic and pantographs have if one of the two power sections went dead as the power performed very well on the line. Unforeseen problems feeds were through the section insulators. that have arisen have been addressed and these problems have been solved. Constant tensioning was implemented on the new Cherry Street extension of the 514 line using Conclusion K+M/Pfisterer constant tension spring devices with trolley wire change clamps for the expanding overlap The Toronto Transit Commission is purchasing new rails. This will keep contact wires at a tension of 891 daN Bombardier Flexity streetcars equipped with pantograph [2,000 lbs] regardless of ambient temperature. current collectors to replace the existing fleet of CLRV and ALRV streetcars with trolley pole current collectors. Several operational issues have occurred with joint The first prototype Flexity cars are equipped with both pole and pantograph operation where pantographs have pantographs and trolley poles. Existing cars and new cars been snagged. Some of these have been due to pole will operate simultaneously until the new fleet of dewirements damaging frog gliders which in turn have streetcars has been delivered and placed in service with damaged pantographs. Adjustments have been made to existing streetcars being replaced as new streetcars are put prevent damaging the gliders and operator instructions for in service. backing up cars have been issued to prevent pole snagging.

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Electrical tracking on section insulators has caused Fig. 18 Constant tension spring device false indications of the line being alive. Insulators on Fig 19 Constant tensioned overlap for poles and conducting runners have been replaced with ceramic pantographs material to reduce carbon buildup. Crews still clean insulators periodically to ensure tracking does not occur. Fig. 20 TTC linemen working Some arcing occurs at section insulators and arc blowout Table 1 Contact Wire Tension Chart devices have been implemented.

Half tension trolley wire on curves when connected to full tension on tangents at trolley frogs has allowed some pantographs to push the wire too high and cause snagging. Spreaders have been installed between the two wires beyond frogs to make the wires rise up together.

The problems encountered are not systemic but nuisance and have been rectified as they have occurred.

ACKNOWLEDGEMENTS

The authors wish to acknowledge the support of the Toronto Transit Commission and HNTB, Incorporated during the preparation of this paper. The views presented herein are those solely of the authors and in no way reflect the opinions or beliefs of the Commission, HNTB, Incorporated or any other entity.

END NOTES

Fig. 1 CLRV Streetcar Fig. 2 ALRV Streetcar Fig. 3 Flexity Streetcar with trolley pole Fig. 4 Flexity Streetcar with pantograph Fig. 5 TTC designed carbon shoe for trolley poles Fig. 6 Proposed articulated shoe for trolley pole Fig. 7 Pullover assemblies Fig. 8 Trolley frog deadend Fig. 9 Trolley frog with gliders Fig. 10 Adjustable crossing pan with gliders Fig. 11 Original section insulator with diodes Fig. 12 New section insulator arrangement with diodes Fig. 13 Diode section insulator schematic Fig. 14 Diode section insulator arrangement-Broadview & Gerrard Fig. 15 Bridge protection fiberglass trough Fig. 16 Saint Clair Station wood trough and spacer bar Fig. 17 Conductor rail details

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